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Erosion, due to recent heavy rainfall, has become an issue with bridge stability. Researchers at the Texas Transportation Institute are researching ways to predict erosion near bridges to prevent failure.

Water damage

Researchers work to stop erosion of Texas bridges from rain

By: Stephanie McMillen

Posted: 8/6/07

The Texas Transportation Institiute (TTI), a member of the Texas A&M University System, is working to ensure the safety and integrity of Texas bridges with funding from the Texas Department of Transportation (TxDOT).

Increased summer rainfall around the state has put emphasis on erosion around bridges. In addition to that, focus has been put on the structural integrity of bridges because of the collapse of the Interstate 35W bridge in Minneapolis, Minn., on Wednesday.

Paul Krugler is a pavement materials research engineer at TTI and former director of research for TxDOT.

"Bridge research is one of five technical areas of TxDOT's research program," Krugler said. "The bridge area of research is one of the highest funded among the five."

TxDOT conducts routine inspections of each bridge at least once every two years, classifying it by condition according to federal and state requirements, Krugler said.

"According to a TxDOT publication, Texas has 49,829 bridges, about 40 percent more than any other state," Krugler said.

Recent heavy rainfall has emphasized the importance of TTI's research on erosion around bridges.

TxDOT maintains a scour-critical list, which identifies bridges that have experienced enough erosion that puts them at the highest risk of failure.

Jean-Louis Briaud, a professor in the Department of Civil

Engineering, is working with TTI's Geotechnical and Geoenvironmental Program to develop a more accurate way to predict erosion around bridge pilings.

"The criteria used to classify a bridge on the scour-critical list is highly conservative and may not be accurate based on what we've already determined through our studies and extensive research in the laboratory," Briaud said

"I want to make it clear that no matter how a bridge is constructed, obtaining a zero-percent risk of failure is not possible," Briaud said. "There are simply too many variables, but with research we can more accurately determine those bridges that are indeed at greatest risk."

Each year, TxDOT bridge experts and bridge researchers from Texas universities, four from TTI and A&M, meet to recommend specific new research projects to TxDOT's Bridge Research Management Committee.

"The Bridge committee then determines which projects appear to have the most potential to provide benefits. Selected new research projects are awarded to universities through a competitive proposal evaluation system," Krugler said.